function like(btn, entityType, entityId, entityUserId, postId) {
    $.post(
        CONTEXT_PATH + "/like",
        {"entityType":entityType, "entityId":entityId, "entityUserId":entityUserId,"postId":postId},
        function (data) {
            data = $.parseJSON(data);
            if(data.code == 0){
                $(btn).children("i").text(data.likeCount);
                $(btn).children("b").text(data.likeStatus == 1 ? "已赞" : "赞");
            }else {
                alert(data.msg);   //此处失败是通过控制器通知统一处理
            }
        }
    );
}